System MAX by Jakub Andruszkiewicz and Konrad Paluszek based on the concept by Lech Ohrysko
pass: 13+ PC, any distribution (but see 2♦ opening)
1♣: 8-12 PC, 1) no shortness, no 54 majors, no 6-card major or 2) 44(41) 3) (53)(41) 4) (42)(61) 5) 7-card minor with 2+♥, 2+♠
1♦: 0-7 PC, any distribution
1♥: 8-12 PC, ♥ shortness, 3-5 ♠ or 6+ ♥, 3- ♠
1♠: 8-12 PC, ♠ shortness, 3-5 ♥ or 6+ ♠, 3- ♥
1NT: 8-12 PC, (54)/55/(64) ♥♠ or 55/(64) ♣♦
2♣: 8-12 PC, 3-4 ♥, 3-4 ♠, minor shortness, 5+ cards in the other minor
2♦: 5-card major, 5-card minor, at most 2 cards in the shorter major, 13-17 (18) PC
2♥: 8-12 PC, 55 with minor shortness/5M6m11 ♥♣ or ♠♦
2♠: 8-12 PC, 55 with minor shortness/5M6m11 ♠♣ or ♥♦
Vulnerable both 3♣/♦ and 2NT promise a 7-card suit
2NT: destructive preempt with clubs or diamonds
3♣: constructive preempt
3♦: constructive preempt
3♥: preempt
3♠: preempt
3NT: minor 7+-card with AKQJ, no honours highers than J aside (excluding single Qs)